In Fig. REF  we display \(24\, \mu \rm m\)  emission maps calculated on the basis of
our Wolf-Rayet nebula model Run-Base, using the RADMC-3D code. The surface brightness
is plotted in the linear scale in \(\rm erg\, \rm cm^{2}\, \rm s^{-1}\, \rm arcsec^{-2}\) 
for several viewing angles and the images are calculated excluding the hot dust-free
Wolf-Rayet gas, see [1]}. On each panel the central white
cross marks the position of the star.
The first column of panels displays the time-dependent edge-view evolution of the
close circumstellar medium of the massive stars. Before the evolution of the blue
supergiant star, the asymmetric wind generates a bright oblate disc-like
shape extending in the equatorial plane of the star (Fig. REF a).
This model does not have a long phase transition interval \(\Delta t\) , and the hot
Wolf-Rayet wind directly interacts with the dense equatorial colder gas. This
interaction region emits in the mid-infrared, which produces the bipolar
morphology (Fig. REF d). As the phase transition ends, the nebula
further extends and become fainter at the poles, while conserving its overall
bipolar bubbly shape.
The second column of panels plots the same sequence of images considered with
an inclination angle \(\theta =45\)  with respect to the plane of the sky.
The situation is qualitatively the same as for \(\theta =0\) , except that
the bright infrared equatorial ring appears as an ellipse (Fig. REF e,h).
The last column of panels displays top-viewed nebulae, which, as a consequence of
the 2.5D nature of the simulations, look like rings extending away from the
evolving central star (Fig. REF f,i). The maximum emission region is
the interaction layer where the Wolf-Rayet wind reaches the termination shock
of the blue supergiant nebula (Fig. REF d,e,f).
